Americans spend up to ten percent or more of their waking hours travelling between home, work, school and shopping facilities. In addition, they spend many more hours on the highways travelling for pleasure. This represents a substantial opportunity for advertisers to reach their potential customers with roadside advertisements. In the past, such advertisements were communicated by way of billboards which were placed along the highways. This advertising occurs at a time when the motorists are most likely to respond. Often the response to this advertising is immediate in that the driver leaves the highway and patronizes the establishment which placed the advertisement. The ability to communicate a message at the precise time the receptor is willing to respond is the goal of virtually all commercial communications. If the advertiser has direct control over the timing of the advertisement transmission, the effectiveness of the advertisement may be more directly observed and correlated.
In many locations, however, billboard advertisement along the national highways is forbidden and is likely to be banned in many more locations owing to present day environmental and aesthetic considerations. Therefore an inexpensive and convenient method of communicating service information is extremely desirable to replace the locality-specific billboards.
Perhaps more importantly, the motorist needs roadway regulatory and advisory information to safely and efficiently travel to his or her destination. A system for communicating current roadway safety information, such as speed limits, road conditions, traffic density, accidents, and other obstructions to the flow of traffic, in an easily assimilated format, would assist the driver to safely adjust to potential problems. For this type of information to be useful it must be both accurate and timely. It is not uncommon for highway advisory signs to be missed by drivers due to their being obscured by other traffic, obstructions to vision such as rain, snow or fog, or the driver's attention being directed elsewhere at the time the sign is readable.
Similarly, navigational information such as the proximity of desired exits from controlled-access highways or turns off of the current roadway, would assist the driver to prepare for and make directional turns both efficiently and safely. Thus, on-board navigational systems which would automatically determine the present location of the vehicle and provide directions to a desired destination to assist the driver when traveling in unfamiliar areas is also desirable.
Improvement in the art of communicating traffic and commercial information to drivers has been the subject of numerous efforts in the past. U.S. Pat. No. 3,899,671 (Stover) discloses an automobile communication system which consists of radio broadcast stations located along highways and receiving devices located in the vehicles so that the driver can receive information pertinent to the location of the transmitter. Stover further discloses that the driver may instruct a device in the vehicle system as to which highway the driver desires to travel or to select certain types of information from that broadcast.
The system disclosed by Stover utilizes a transmitting means which broadcasts signals which contain detailed information pertinent to the location of the transmitter. Such information may concern traffic control signals, intersections and exits, or highway identification messages. This information is stored in a memory device associated with the transmitter and broadcast on a cyclic schedule.
This information is received by vehicle-mounted receiving means and selectively edited in accordance with the instructions provided by the operator. The desired information is then presented to the driver in either audible or visual format. The data processor in the vehicle must wait for the desired information to be transmitted to it before the information is selected and presented. This limits the time available for the transmitter to complete an information cycle. As the broadcast cycle becomes extended, the transmitter power must be increased and the broadcast time extended to insure that the information is reliably received before the vehicle passes the transmitter. The broadcast transmitters also must be separated in either space, time or frequency to avoid interfering with one another.
Stover teaches that the information transmitted by the system may be altered in real time by connecting remote sensors to the transmitter input. An application suggested by Stover is the addition of sensors which detect the status of traffic signals which affect traffic beyond the location of the transmitter. This information is then used to access appropriate messages in the transmitter database. Stover does not suggest, however, that non-routine information such as changing highway conditions or traffic patterns could be incorporated into the broadcast signal in an interactive, real-time manner. Neither does Stover suggest the incorporation of commercial messages into the system.
U.S. Pat. No. 4,481,584 (Holland) discloses a method and apparatus for providing highway information by means of a microprocessor and a plug-in data cartridge. The plug-in cartridge permanently stores in digital form a multitude of data related to services and other pertinent information available along a selected roadway. Each of these data is indexed according to distance or mile marker indicators along the roadway. A keyboard serves as a data entry means for the motorist to manually input the required location information necessary to indicate the section of highway for which he or she desires roadway information. In use, the driver must manually provide to the computer the vehicle present location relative to a highway mile marker and the present direction of travel. If the driver, for whatever reason, is unable to determine the present vehicle location, he must wait until he sees the next mile marker, thereby losing possibly relevant desired information. The system may also allow the selection of type of information desired. However, Holland does not teach that the driver may preselect the type of information desired for each location; rather, a complete set of different instructions must be provided for each location.
The computer in Holland combines this information with the data in storage and provides the programmed response. The system retrieves all stored information related to the data input by the driver and provides a visual display and/or audible speech synthesis means for conveying the information to the driver.
The data storage module described by Holland may be a plug-in magnetic disk, tape or laser disk which has been programmed with the available or desired information on a highway or system of highways. Holland suggests arranging the data modules by state or interstate highway systems. The information contained in storage is current as of the time the module is programmed. Holland does not suggest any method of providing real-time update or rapid revision to the information available to the motorist, nor does he suggest that complete messages may be synthesized from information existing in the database.
U.S. Pat. No. 4,816,827 (Baloutch et al.) discloses a system of broadcasting signals to activate audible messages associated with traffic signs. Baloutch describes an infrared transmitter which transmits an encoded signal peculiar to the type of traffic sign. The transmitter is triggered by a sound detector which detects the approach of a vehicle. A receiver in the vehicle receives and translates the code into an audible signal peculiar to the type of traffic sign. Baloutch further discloses that an additional coded signal may be activated remotely as required to provide warning of traffic conditions ahead. Among other disadvantages, since infrared signals are dispersed by rain, snow, heavy fog or other high humidity atmospheric conditions, this system would work well only during relatively clear atmospheric conditions.
U.S. Pat. No. 4,023,017 (Ceseri) discloses a complex traffic control system utilizing groups of detectors to determine traffic conditions, a central controlling computer, and a communications system to communicate encoded and clear messages between detectors, traffic warning signs along the roadway, and to receivers in vehicles. Ceseri describes a system wherein the detectors are grouped on posts along a highway and determine vehicle movement and ambient environment information. Information such as vehicle speed, traffic density, precipitation, and temperature are collected by the detectors and transmitted over cable or by radio broadcast to a central computing system. The central computer determines if these parameters, along with highway design information such as grade, number of lanes, and road surface, are within expected ranges. Combinations of these factors which are not within the predetermined parameters are used by the central computer to activate warning signs and to alert human controllers that problems may exist. The human controllers then take appropriate action such as turning on warning signs or broadcasting warnings to vehicle-mounted receivers. Audio or visual devices associated with the receivers alert the drivers to the abnormal conditions.
U.S. Pat. Nos. 4,527,155 (Yamaki et al.) and 4,937,570 (Matsukawa et al.) address the presentation of data from vehicle-mounted navigational systems to the driver. Yamaki utilizes a computer provided with coordinate data and a direction of travel sensor to rotate visual data for presentation to the operator. Yamaki discloses a method of rotating diagrammatical displays, i.e. a "map", so that the direction of travel is always presented in one direction, while simultaneously presenting the map labels in an upright, easily read format.
Matsukawa discloses a route guidance display device which receives signals from an on-board computer which utilizes an external memory programmed with map data, an input device which indicates starting and destination points, and direction and distance sensors. The display provides in a three dimensional diagram visual indication of the appropriate direction of travel at intersections between the starting point and the destination.
U.S. Pat. No. 3,105,119 (Cory, Jr., et al.) discloses a highway communications system which utilizes a dual transmitter system to first enable a receiver with a trigger signal in one frequency band followed by a message signal in a different band. The communications system transmits entire messages to the in-vehicle receiver. Cory neither teaches nor suggests how to increase the number of messages conveyed to the driver.
U.S. Pat. No. 3,105,120 (Hanysz) discloses a highway communications system which broadcasts messages to vehicles traveling along a roadway by use of a dual transmitter arrangement. Hanysz describes how a first transmitter provides a signal which enables an in-vehicle receiver which is thereby prepared to receive the information transmitted by a second transmitter. Hanysz does not suggest, however, how a single transmitter could provide unidirectional signals to a receiver.
U.S. Pat. No. 4,630,209 (Saito et al.) discloses a vehicle-based system to electronically present to the driver a map of the area in which the driver is operating. This provides the driver with information on where streets, intersections etc. are located relative to each other. Saito does not however suggest how the driver can ascertain where he is relative to any particular point on the electronic map.
U.S. Pat. No. 4,190,819 (Burgyan) discloses a programmable automobile information system utilizing a tape recorder to deliver sequential prerecorded messages. The recorder receives start and stop signals from a microprocessor which translates distance traveled information from the vehicle odometer into appropriately timed signals to operate the recorder. The recorded message may be routing directions to a preselected destination or information about the area through which the vehicle is passing. Burgyan further discloses a means for the operator to resynchronize the tape with a landmark described on the tape. Burgyan does not however suggest how the system could be automated with location information for a randomly moving vehicle.
U.S. Pat. No. 4,350,970 (von Tomkewitsch) describes a system for determining traffic situations and providing route guidance and other information to vehicles on a highway system. This system utilizes unspecified transmitting and receiving devices to communicate data carried from one roadside site to another by the vehicle itself, along with a time measurement for completing one part of a preplanned route. That information would then be used to provide route information to assist the driver in travelling to the next roadside site. Since von Tomkewitsch does not specify a recommended communications system for the transmission of such information, it is not clear how the system communicates with a large number of vehicles simultaneously at each location. This patent also does not address the immense amount of computational time needed to recommend optimum routes to each passing vehicle.
In addition to prior art patents, there have been a number of studies conducted by state and federal transportation agencies which provide insight into the types of displays that are most effective in communicating with drivers in moving vehicles. These studies provide analyses of the requirements of safety and hazard warning systems. A study completed by Commonwealth Research Corporation in April, 1982, provides an analysis of the requirements that must be met in order to successfully build a dedicated safety and hazard warning communications system for vehicles. This study specifically rules out receivers operating in anything but standard broadcast bands because of the cost of installing a different receiver and a separate antenna in vehicles.
The U.S. Department of Transportation (DOT) has started to develop the concept of the Intelligent Vehicle Highway System (IVHS) wherein dynamic roadway information could be provided to the driver. Early DOT concepts envisioned using sensors to collect and feed roadway information to central computers for analysis. The results would be retransmitted back to the driver via satellite communication networks, AM/FM radio networks or other sophisticated and expensive technologies. This concept was formalized in the DOT Policy Statement in 1989 and published in the 1990 annual report.
The International Congress on Transportation Electronics, sponsored by the Society of Automotive Engineers and held in Detroit, Mich. in October, 1990, provided a forum for most of the international projects that are concerned with roadway communication systems, vehicle navigation, and traffic management systems. Several papers published in "Vehicle Electronics in the 90's: Proceedings of the International Congress on Transportation Electronics", outline systems under development by governments and companies in Asia, Europe, and the United States. None of these papers describe systems under development that would meet the low cost requirement for wide spread utilization by non-business users.
The electronic communications art is rapidly becoming the primary communications method by which an individual receives information. Modern day society relies on the electronic communication of information by either radio or television. Communication of vehicle-specific information to motorists, however, is not well developed. The adaptation of this medium to real-time vehicle operations depends on the ability to present pertinent information to the driver in a timely manner without greatly distracting him or her from the driving task.